Process of making nickel salts and recovering the acid used.



UNITED STATES PATENT OFFICE.

HORACE L. WELLS, OF NEW HAVEN, CONNECTICUT, ASSIGNOR F TWO-THIRDS TO MARY H. KING, OF EAST ORANGE, NEW JERSEY.

PROCESS OF MAKING NICKEL SALTS AND RECOVERING THE ACID USED.

No Drawing.

Haven, in the county of New Haven and State of Connecticut, have invented a new and useful Process of Making Nickel Salts 1 and Recovering the Acid Used; and I do hereby declare the following to be a full, clear, and exact description of the same.

My present invention relates to a new and useful method or process for separating and extracting nickel, iron, cobalt, copper, gold, silver and metals of the platinum group from a matte consisting largely of nickel and copper sulfid, or a combination of these with other metals, or a combination of all or some of the metals above indicated and with the nickel extracted to prepare a nickel plating salt. I

The object of my invention is to produce an efiicient and comparatively inexpensive process for preparing nickel salts.

I am aware that nickel salts suitable for plating and other pur oses have been produced, usually by treating metalllc nickel or ing metallic nickel or the oxid of nickel and at the same time recover the solvent used.

In carrying out or practicing my process I pulverize the matte and then treat it one or more times with hydrochloric acid diluted to contain from ten to thirty per cent. actual acid, the matte being treated with the acid until the nickel is largely dissolved which is indicated b sulfureted hydrogen {a gas generated by t e reaction at first ra idly given off) being slowly given, ofi', t e

time required being usuallyfrom one (1') to ten (10) or more hours dependent upon the quantity of matte treated, the chemical composition and physical condition of the same, the strength and amount of the acid used, the amount of agitation given and the degree of heat applied during the treatment of the mixture. When treating the matte with the dilute hydrochloric ac d, the temperature of the acid ranges from 180 Fhr. to a point below 212 Fhr. The result of this treatment is the production of a green colored solution, which consists of nickel chlorid principally, there being present also certain Specification of Letters Patent. Application filed June a, 1911. Serial No. 631,897.

Patented Oct.- 1, 1912.

quantities of iron chlorid and cobalt chlorid, if the matte contains the sulfids of same, and some chlorid of copper; and a black residue, being the unaffected portion of the matte consisting of copper sulfid princithe acid for the purpose of economy in theuse thereof, as when the acid is strong, hydrochloric acid gas is given ofi very rapidly on the application of heat, whereas sufiiciently diluted acid will stand the application of heat without appreciable loss by evaporation during the operation.- I then take the solution resulting from the action of the aqueous hydrochloric acid on the matte, which consists of nickel chlorid principally, and treat fresh matte in a pulverized state therewith at the previously mentioned temperature and with H S gas. In this last mentioned step a reaction is obtained which results in the extraction of nickel from this matte, due to the action of any remaining free hydrochloric acid, and also replacing the copper that may be contained in the solution with nickel of the matte; in other words, dissolving more nickel sulfid and replacing the small quantity of copper that may be contained in the solution by a portion of the nickel contained in the fresh matte, producing a solution consisting of nickel chlorid principally, with some iron and cobalt chlorids, if the sulfids of the same were present in the matte, and a residue, being the unafiected portion of the matte plus the copper sulfid thrown out of the solution with which the fresh matte was treated. The residue thus obtained may be added to the fresh matte and treated as heretofore described, or, without being added to new matte, it may be treated in a similar manner as if it were fresh matte. I then take the solution last obtained and expel the sulfureted hydrogen, by boiling or passing air or steam through it. I take this solution and add thereto and mix therewith an amount of black oxid of nickel or chlorin in some form suflicient to oxidize the ferrous salts to ferric salts and add sufficient calcium carbonate or ammonia water to precipitate the iron as hydroxid or as a basic salt. The product thus produced is then filtered; to the filtrate I add a quantity of nickel oxid or 'chlorin in some form and a carbonate sufficient to precipitate the black oxid of cobalt. I filter, recovering the cobalt by the usual processes and to the filtrate, being a very pure chlorid of nickel, while either hot or cold, I add a sufficient amount of sulfuric acid to react with the nickel chlorid present, and a suiiieient amount of ammonium sulfate to form the double ammonium nickel sulfate. I allow the liquid to cool and the double salt crystallizes out. The salt is separated and the mother liquor is used over again with fresh hydrochloric acid in dissolving fresh matte. If desirable the mother liquor may be first evaporated, and a further quantity may be crystallized out.

In order to obtain crystallized nickel sulfate (NiSO 7H O), in palce of the nickel ammonium sulfate, (Ni(NH )2(SO 2) the latter salt is placed in a suitable vessel or furnace, such as, for instance, upon the hearth of a reverberatory furnace, and a proper amount of sulfuric acid added thereto, the heat causing the evaporation of the liquid and the production of nickel sulfate crystals. The temperature should not rise as high as the boiling point of sulfuric acid, nor should the temperature be high enough so that any ammonium sulfate be decomposed. The result of heating gently and stirring together the double salt of nickel ammonium sulfate and sulfuric acid is a pale greenish yellowish mass, semi-fluid while hot; I remove this from the fire and allow to cool and break up, without long exposure to the atmosphere. I then treat the mass with about its own weight of cold water and agitate. I then filter obtaining a cake inthe filter and a filtrate. The cake consists of very pure anhydrous nickel sulfate, which is heated with hot water and agitated until the cake dissolves and from this solution the nickel vitriol NiSOJH O is crystal- 7 lized out.

The filtrate obtained as outlined above contains only a little nickel being chiefly ammonium sulfate and sulfuric acid which is suitable and in proper proportions for preparing the double salt used in this process, which gives me an entirely original and remarkably simple and cheap process for preparing NiSOJH O and using over and over the reagent-snecessary to produce this result. Or, I take the final solution of nickel chlorid, and evaporate the same to dryness with an equivalent quantity of sulfuric acid, obtaining sulfate of nickel and hydrochloric acid gas which I collect in water. The sulfate of nickel is then dissolved in hot water, and either crystallized as such, or converted into the double sulfate by the addition of the equivalent quantity of sulfate of ammonia, which is then separated by cooling or evaporating the solution.

I claim 1. The herein described method of producing nickel sulfate from a matte containing nickel iron and other metals and recovering the acid used in the process which consists in pulverizing the matte, then heating and agitating the same in hydrochloric acid having a greater solvent action on the nickel and iron than on the other metals in the matte, then by adding to the solution obtained an oxidizing agent and in any suitable manner precipitating the iron from said solution, adding to the solution obtained sufficient sulfuric acid to react with the chlorid present and sufiicient ammonium sulfate to form the double nickel ammonium sulfate, recovering the sulfate as crystals and utilizing the mother liquor obtained to dissolve fresh matte.

2. The herein described method of producing nickel sulfate from a matte containing nickel iron and other metals, which comprises treating pulverized matte with hydrochloric acid, adding to the solution thus obtained an oxidizing agent and in any suitable manner precipitating any iron from the solution, adding sufficient sulfuric acid to act with the chlorid present and sufficient ammonium sulfate to form the double nickel ammonium sulfate, and recovering the said double nickel ammonium sulfate as crystals.

3. The herein described process of producing double nickel ammonium sulfate from a matte containing nickel iron and other metals,'which comprises treating pulverized matte with dilute hydrochloric acid, treating the solution thus obtained with fresh matte and sulfureted hydrogen, boiling to expel the sulfureted hydrogen, adding an oxidizing agent and in any suitable manner precipitating any iron from the solution, adding sufficient sulfuric acid to react with the chlorid present and sufficient ammonium sulfate to form the double nickel ammonium sulfate, and recovering the said double nickel ammonium sulfate.

4. The herein described method of producing double nickel ammonium sulfate from a matte containing nickel iron and other metals, which comprises treating pulverized matte with dilute hydrochloric acid, treating the solution thus obtained with fresh matte and sulfureted hydrogen, boiling to expel the sulfureted hydrogen, adding black oxid of nickel to oxidize ferrous saltsto ferric salts and adding calcium carbonate to precipitate iron, adding a sufiicient specification in the presence of two subscribamount of sulfurlc afcf ld to react with thle ing witnesses. chlorid present and su cient ammonium su fate to form the double nickel ammonium HORACE-L WELLS 5 sulfate, and recovering the double nickel am- Witnesses:

monium sulfate. FREDERIO C. EARLE, In testimony whereof, I have signed this CLARA L. WEED. 

